HTML 5 is the next revision of the Hypertext Markup Language (HTML), the standard programming language for describing the contents and appearance of Web pages. HTML 5 was adopted by the new HTML working group of the World Wide Web Consortium (W3C) in 2007. This group published the first public draft of HTML 5 in January 2008, but refinements are expected to continue for several years before HTML 5 becomes a formal recommendation.
In theory, HTML 5 will allow the Web browser to become a development platform. A primary goal for HTML 5 is to ensure interoperability among browsers so that Web applications and documents behave the same way no matter which HTML 5-compliant browser is used to access them. (Older browsers that do not support HTML 5 will be able to ignore the new constructs and still produce legible Web page s.)
HTML 5 is expected to offer numerous improvements over HTML 4, including:
- New parsing rules for enhanced flexibility
- New attributes
- Elimination of outmoded or redundant attributes
- Immediate-mode drawing
- Drag and drop
- Back button management
- Timed media playback
- Offline editing
- Messaging enhancements
- Detailed rules for parsing
- MIME and protocol handler registration
Contributing to IBM's DeveloperWorks site, Elliote Rusty Harold explains that HTML 5 will be:
...instantly recognizable to a Web designer frozen in ice in 1999 and thawed today. There are no namespaces or schemas. Elements don't have to be closed. Browsers are forgiving of errors. A p is still a p, and a table is still a table. At the same time, this proverbial unfrozen caveman Web designer would encounter some new and confusing elements. Yes, old friends like div remain, but now HTML includes section, header, footer, and nav as well. em, code, and strong are still present, but so are meter, time, and m. img and embed continue to be used, but now there are video and audio too.
Ian Hickson demonstrates new HTML 5 elements in this Google Developer's Talk.